Investigating a highly significant QTL for milk protein content segregating in Sarda sheep breed close to the caseins cluster region by whole genome re-sequencing of target animals

Abstract Text: The aim of this work was to investigate by whole genome re-sequencing of target animals a significant QTL for milk protein content segregating in the Sarda sheep breed. The QTL mapped 85.34 Mb on OAR6, close to the caseins cluster. Two  animals with high probability to be alternative homozygous and one heterozygous at the causal mutation, were re-sequenced with Illumina HiSeq sequencer. Sequences mapped to the Ovis aries v3.1 reference genome. The average coverage ranged from 9.41 and 17.20. SnpEff variants classification according to Ensembl annotation mapped 2,434 SNPs on 25 annotated genes in the focused region. Twenty non-synonymous SNPs were identified in 13 annotated genes. Three non-synonymous SNPs were in the coding regions of CSN1S1 (85102965, C/T), CSN1S2 (85117333, T/C) and CSN2 (85194568, C/G).

Keywords:

Dairy sheep

Protein content

Caseins genes